Inferior alveolar nerve block by injection into the pterygomandibular space anterior to the mandibular foramen: radiographic study of local anesthetic spread in the pterygomandibular space. (9/174)

We studied the spread of local anesthetic solution in the inferior alveolar nerve block by the injection of local anesthetic solution into the pterygomandibular space anterior to the mandibular foramen (anterior technique). Seventeen volunteers were injected with 1.8 mL of a mixture containing lidocaine and contrast medium utilizing the anterior technique. The course of spread was traced by fluoroscopy in the sagittal plane, and the distribution area was evaluated by lateral cephalograms and horizontal computed tomography. The results indicate that the contrast medium mixture spreads rapidly in the pterygomandibular space to the inferior alveolar nerve in the subjects who exhibited inferior alveolar nerve block effect. We concluded that the anesthetic effect due to the anterior technique was produced by the rapid distribution of anesthetic solution in the pterygomandibular space toward the mandibular foramen, and individual differences in the time of onset of analgesia may be due to differences in the histologic perineural tissues.  (+info)

Craniofacial growth and skeletal maturation: a mixed longitudinal study. (10/174)

The purpose of this study was to investigate the relationship between craniofacial growth and skeletal maturation. The material consisted of the cephalometric and hand-wrist film pairs of 35 males and 43 females (78 subjects) whose development was followed for a period of 4 to 7 years. The subjects were grouped according to their skeletal maturation. Their mean ages were: Group I 10.27, Group II 11.55, and Group III 14.79 years, respectively, at the beginning of the observation period. Intra- and inter-group differences were examined through paired t-tests, and Pearson correlation analysis was used to detect the relationship between craniofacial growth and skeletal maturation (percentage growth potential). The results show that the middle cranial base (T-W) maintained its stability in all pubertal growth periods. However, posterior cranial base length (T-Ba) increases significantly (P < 0.001) throughout the same period. There were similar increases in the vertical dimensions of the face and alveolar height throughout pubertal growth. Despite the intensified increases in both the sagittal and vertical directions, facial characteristics were constant in the sagittal direction. The skeletal development (percentage growth potential) has clearly been effective in the vertical facial development commencing in Group I and reaching its maximum level in Group II. However Cd-Go was the exception.  (+info)

Morphological parameters as predictors of successful correction of Class III malocclusion. (11/174)

The aim of the study was to assess pre-treatment cephalometric parameters and measurements of the size of the apical bases as predictors of successful orthodontic correction of Class III malocclusions. Pre- and post-treatment lateral cephalograms and study models of 80 completed Class III subjects were examined to obtain 23 cephalometric parameters taken mainly from the analyses of McNamara and Schwarz, and to measure the size of the apical bases. Success of occlusal correction was evaluated as the percentage change of peer assessment rating score during treatment, which was used as the dependent variable in multivariate statistical analyses testing the predictive value of the parameters assessed. No improvement in the Class III skeletal pattern occurred during treatment and the treatment effects were confined to dentoalveolar changes. With the exception of the percentage midfacial length/mandibular length ratio, the net sum of maxillary and mandibular length differences, the mandibular ramus height/mandibular body length ratio and the gonion angle, most cephalometric parameters of pre-treatment craniofacial morphology assessed were poor predictors of successful correction of Class III malocclusions. Assessment of the size relationship of the maxillary and mandibular apical bases was the strongest predictor of occlusal correction achieved and may serve as a valuable diagnostic addition in the prediction of successful treatment outcome.  (+info)

The effect of zigzag elastics in the treatment of Class II division 1 malocclusion subjects with hypo- and hyperdivergent growth patterns. A pilot study. (12/174)

The aim of this study was to investigate the effect of zigzag elastics in the treatment of Class II division 1 malocclusion subjects with hypo- or hyperdivergent growth patterns. Two groups were established, each consisting of 10 subjects classified as hypo- or hyperdivergent according to their pre-treatment SN-GoGn angle. The cephalometric radiographs taken before and after an elastic application period of approximately 4 months were used to generate 22 variables. In both groups, there were no statistically significant differences in the vertical position of the lower molars, the SN-GoGn angle or the inclination of the lower incisors, whereas the sagittal skeletal relationship was improved as a result of an increase in the SNB angle and the mandibular length (P < 0.01). Upper incisor extrusion was statistically significant in both groups (P < 0.05). The downward rotation of the occlusal plane and the increase in overbite were found to be significant in the hypodivergent group (P < 0.05). Significant differences were observed between the groups in the extrusion of the upper incisor, the inclination of the occlusal plane, and the amount of overbite (P < 0.05). The results show that the zigzag elastic system is preferable, especially in hyperdivergent Class II division 1 subjects, as the use of such elastics does not cause an unfavourable effect on vertical jaw base relationship.  (+info)

Functional regulator treatment of Class II division 1 malocclusions. (13/174)

This controlled retrospective study aimed to identify the contribution of skeletal and dental changes in the correction of Class II division 1 malocclusions using Frankel's functional regulator II (FRII), with reference to a concurrently recruited control group. One hundred and thirty-eight patients with Class II division 1 malocclusions were identified, those accepting treatment forming the study group and those declining treatment the control group. The study group (n = 70) were treated with a Frankel appliance. Pre- and post-treatment observation cephalometric radiographs were analysed and compared. Mean values for both skeletal and dental variables in the control group were remarkably consistent throughout the study period; however, this masked individual variations in this group. The skeletal variables in the study group that showed statistically significant differences from the control group were SNB, ANB, BaNA and ANS-Me, but none of these was sufficiently large to be regarded as clinically significant. Dental variables showed clinically and statistically significant differences, including a 10 degree reduction in UI-Max and 3.1 degree increase in LI-Mand. The Frankel appliance was thus found to be effective in producing desirable occlusal and dental changes in the majority of patients treated.  (+info)

A cephalometric inter-centre comparison of growth in children with cleft lip and palate. (14/174)

AIM: To examine whether the treatment provided by the Mount Vernon Cleft Team produces craniofacial growth outcomes comparable with that of the Oslo Team. LOCATION: Mount Vernon Hospital, Middlesex, UK. DESIGN: A retrospective cephalometric investigation. SUBJECTS: Seventy-five Mount Vernon children and 150 Oslo children with complete unilateral or bilateral clefts of the lip and palate METHOD: The subjects were matched for age, gender, and cleft type, and their radiographs were digitized. The radiographs from each site were grouped according to patient age (9-11 or 14-16) and cleft classification (bilateral/unilateral). Patients with associated craniofacial anomalies were excluded from the study. RESULTS: Of the four variables studied (SNA, SNPg, NGn, sNANsPG) significant differences in maxillary growth were noted for bilateral and unilateral cleft groups at 14-16 years of age. The soft tissue profile was significantly flatter in bilateral and unilateral Mount Vernon cases at 14-16 years. The craniofacial growth exhibited by the Mount Vernon patients demonstrated 3.9-5.1 degrees reduction in maxillary prominence with respect to the Oslo sample. The bilateral cases from Mount Vernon had greater anterior face heights at 14-16 years. CONCLUSION: The treatment provided by the Mount Vernon Cleft team leads to a reduced maxillary prominence in children aged 14-16 years compared with the Oslo sample. This reduction is statistically significant in unilateral cleft lip and palate.  (+info)

The effect of growth hormone therapy on mandibular and cranial base development in children treated with total body irradiation. (15/174)

The aim of the present investigation was to study craniomandibular development during growth hormone (GH) therapy in nine girls and one boy, aged between 7.3 and 16 years, who exhibited pronounced growth reduction after total body irradiation (TBI) and bone marrow transplantation (BMT). Age- and sex-matched healthy children with normal dentofacial development constituted the control material. The investigation data were based on measurements made on lateral skull radiographs taken at the start and, on average, 6 months after cessation of GH treatment. The control group comprised similar longitudinal cephalographic records. The results showed that GH therapy in patients who exhibited growth retardation after TBI and BMT had only a minor effect on cranial base dimensions, probably due to the fact that the development of this area is completed at a relatively early age. The effect of GH treatment on mandibular growth was very obvious. The dimensional increase of the mandibular variables in the patients was equivalent to, or in some cases even exceeded, that of the controls. In relation to basion, the mandibular condyles were displaced in a backward/upward direction in the patient group. Displacement in the opposite direction was recorded in the controls. It seems likely that the development seen in the patients is a reflection of a normalization of the condyle-fossa relationship made possible by enhanced condylar growth. This change should be advantageous for the function of the craniomandibular complex.  (+info)

Measurement of lateral loads exerted on the maxillofacial region by habitual postures. (16/174)

Lateral loads exerted on the maxillofacial region by habitual postures and habits may cause lateral shift or deformity of the mandible. These loads were measured with a desktop dynamic-strain gauge (DPM-600, Kyowa Co.) connected to a small, highly sensitive pressure sensor (PSL-A type, Kyowa Co.), and recorded with an oscillographic recorder (RDM-100A, Kyowa Co.). Measurements were taken with a pressure sensor embedded in silicone impression material placed in a vinyl chloride resin bag, on which pressures were applied. A preliminary study was conducted to obtain a proportional constant and a conversion formula for load calculation. The subsequent main study included 20 healthy male volunteers for load measurement in 12 positions. The mean load exerted on the mandible was 43.7 N when the subjects lay face down and approximately 20 N when they sat resting the lateral part of the chin on the hand, indicating that these loads are greater than regular orthodontic forces.  (+info)